In a bidirectional drive tape cartridge of the type shown in U.S. Pat. No. 3,692,255 in which tape moves at high speeds between two reels and is subjected to high accelerations when the tape direction is reversed, it is important to minimize tape tension variations at the transducer head. Otherwise tape to head contact may be lost and data compromised.
U.S. Pat. Nos. 4,581,189 and 4,466,564 disclose drive belts, typically made of polyurethane, for use in such tape cartridges particularly configured to minimize tape tension variations characterized as flutter. More particularly, the disclosed drive belts are described as having a microscopically rough surface with peak-to-peak roughness ranging in size between 0.2 and 40 micrometers to promote the release of air from between the belt and the tape. This surface roughness, it is believed, is intended to overcome the inherent tendency of polyurethane to exhibit slip-stick motion.